Ink roller fountain

ABSTRACT

An ink transfer system for a rotary printing press wherein a helically grooved transfer roll is provided for effectively transferring toward a plate cylinder an ink volume consistent or equal to the usage requirements at any given point or area on the roll surface as determined by the printed image. The transfer roll has the ability to simultaneously transfer ink reversely back onto the fountain roll by reason of its helical grooves being in light contact with a relatively slowly rotating fountain roll. An offset groove and ball arrangement is provided for one of the distribution rolls in the printing press chain of rollers so as to smoothly oscillate the roll for a more even distribution of the ink transversely of each roll in the ink train. The inner face of each fountain roll mount is slightly relieved so as to direct ink away from the outermost ends of the fountain roll thereby substantially preventing fountain leakage.

United States Patent Harrod INK ROLLER FOUNTAIN Jimmie A. Harrod,Middleport, NY.

[75] Inventor:

[73] Assignee: Moore Business Forms, Inc.,

Niagara Falls, NY.

[22] Filed: March 26, 1971 [2]] Appl. No.: 128,509

Related US. Application Data [62] Division of Ser. No. 885,748, Dec. 17,1969, Pat. No.

[52] U.S.Cl ..l0l/363, 101/365 [51] Int. Cl. ..B4lf 31/06 [58] Field ofSearch ..l0l/350, 363, 364, 365, 366, 101/207, 208, 210,148, 351, 355,360, 330;

Wintzer 101/364 Behringer ..l01/366 X Primary Examiner-J. Reed FisherAttorney-Watson, Cole, Grindle & Watson [57] ABSTRACT An ink transfersystem for a rotary printing press wherein a helically grooved transferroll is provided for effectively transferring toward a plate cylinder anink volume consistent or equal to the usage requirements at any givenpoint or area on the roll surface as determined by the printed image.The transfer roll has the ability to simultaneously transfer inkreversely back onto the fountain roll by reason of its helical groovesbeing in light contact with a relatively slowly rotating fountain roll.An offset groove and ball arrangement is provided for one of thedistribution rolls in the printing press chain of rollers so as tosmoothly oscillate the roll for a more even distribution of the inktransversely of each roll in the ink train. The inner face of eachfountain roll mount is slightly relieved so as to direct ink away fromthe outermost ends of the fountain roll thereby substantially preventingfountain leakage.

2 Claims, 7 Drawing Figures PATENTED JAN 2 3 I973 SHEET 1 BF 3 INKROLLER FOUNTAIN This is a divisional application of co-pending U.S.application Ser. No. 885,748, now U.S. Pat. No. 3,65l,758,filed Dec. 17,1969.

This invention relates generally to printing presses and moreparticularly to an ink transfer system having a transfer roll designedfor maintaining a more complete balance of ink film in the system bypermitting both a forward and reverse transfer during rotation in onecontinuous direction.

One of the inherent difficulties in printing with the rotary printingpress lies in the repeated failure to achieve a suitable balance of inkthrough the system so that as ink is consumed at the plate cylinder onlyan appropriate ink volume consistent with that usage will be transferredfrom the fountain. The presence of too little or too much ink on theprinted image requires the printer to first adjust the extrusion throughthe fountain blade through a process of trial and error, while the pressis in operation, until the desired printed image is achieved. Duringthis interval an extensive amount of paper and man-hours are wastedbecause the increased or decreased amount of ink extruded by thefountain blade must be circulated through the system and the paper withits unwanted image must be expelled through the system completely beforethe press becomes once again productive. Also, for the wide viscosityrange of different inks used during printing, a new adjustment isrequired so that many rotary printing presses are not tailored foreffective transfer of these various grades of ink in a manner whereby aconstant ink film thickness onto the plate cylinder is assuredregardless of ink density.

In an attempt to remedy this situation, various means have beendeveloped for reducing the film thickness from the fountain roll andevenly spreading the film during its travel toward the plate cylinder.For example, ductor rollers have been extensively employed for effectingintermittent contact between the fountain and a first distribution roll.However, this technique only tends to produce undesirable variations inthe film which are difficult to smoothen even with the use of a longchain of distribution rollers. Another technique ineludes the use ofeither a smooth transfer roll or one having spiral ridges or other typesof elevated designs thereon. Such types of transfer rolls prove to beineffective since they only tend to pick up the ink in uneven patchesand thereafter deposit it unevenly.

Also, in rotary press systems, leakage of ink through the fountain hasbeen an almost never ending problem in the industry. In most currentdesigns the length of each fountain roll must be precisely machined soas to lie within a close clearance at both ends against each fountaincheek. After extended use these clearances tend to enlarge to such anextent that leakage occurs as beads of ink escape between the ends ofthe fountain blade and the inner face of each fountain cheek. Other thana repeated wiping of this area, steps have been taken to avoid leakageby designing the fountain cheeks as having slightly sloping surfacesnear the top of their inner faces so that, after the beads of ink travelbetween the point of leakage and the top of each cheek inner face, theywill return back into the fountain reservoir. This technique has notsubstantially reduced leakage because it has been found that most of theink beads will merely drip from the cheek under the force of gravitybefore travelling around the cheek surface toward the relief. in thepresent invention, the fountain roll is mounted so that each end of itsroll surface lies within each end mount or cheek which is designed ashaving a relief presenting a sharp edge in line with the ends of thefountain blade so that the beads of ink may be directed away from thesurface of each cheek directly onto the fountain roll and finally backinto the fountain reservoir.

Another problem in rotary printing presses arousing somewhat of aconcern in the industry involves the currently available technique foroscillating one or more rolls in the system so as to more evenlydistribute the ink film across each roll. This technique makes use of aworm gear and worm for transmitting axial movement to the oscillatingroll. Each of the several moving parts therein require maintenance andperiodic replacement which only increases the probability of costlydowntime for the equipment and additional expenses in operation. Withthe present vibration system, a ball of a specified diameter is mountedfor rotation and planetary movement about the oscillator roll within anoffset groove designed at one end of its axle. Accordingly, fewer movingparts are required which not only reduces the likelihood of extensivedowntime of the equipment but also permits the oscillating axle to bemoved directly by a force parallel thereto thereby avoiding undue wearotherwise attributable to the gear driven oscillators. Accordingly, theinstant invention has for its main object the provision of an improvedtransfer roll for a rotary printing press which will transfer an inkvolume consistent with usage requirements so that a more balanced inkfilm thickness is maintained in the system despite the variation of inkviscosity or the relative amount of ink being extruded through thefountain blade.

Another object of this invention is to provide an ink transfer systemwherein the improved transfer roll is capable of simultaneouslytransferring an amount of ink in either or both directions through thesystem at a rate depending on the usage requirement and/or the change inthe volume of ink available for transfer thereby achieving a morebalanced ink distribution system.

A further object of the invention is to provide an ink transfer systemwherein the improved transfer roll is slightly undersped with relationto press surface speed and the fountain roll is greatly undersped withrespect to press surface speed so that, together with the specific typeof transfer roll design, ink is transferred reversely even duringforward transfer and, after drainage of ink from the fountain, willeffect a total reverse transfer of ink back toward the fountain rollproviding no additional ink is extruded by the fountain blade.

A still further object of this invention is to provide an ink transfersystem wherein the surface of said transfer roll is provided with aplurality of grooves thereon each having at least one radial surfaceforming a sharp juncture with the outermost periphery of the rollsurface whereby forward and reverse transfer to achieved at a ratedepending upon the speed of rotation of the fountain roll.

A still further object of the instant invention is to provide a transferroll as characterized wherein the sharp radial surface departure definesa trailing edge with respect to direction of roll rotation and whereinthe lowermost surface of each groove joins the trailing edge of anadjacent groove thereby creating a leading edge or ramp between grooveswhereby reverse ink transfer onto the fountain roll is effected throughan ink spreading action caused by the leading and trailing edgesrotating against the slower rotating fountain roll.

A still further object of this invention is to provide an improvedoscillating means for the ink transfer system wherein one distributionroll in the ink train of rolls is smoothly oscillated by a force actingdirectly along its axis for evenly distributing the ink between the endsof each roll in the train.

A still further object of this invention is to provide such anoscillating means comprising an offset groove and ball arrangement atone end of one of the rolls in the train so that rotation of such rollcauses axial movement as the offset groove moves about the planetaryball thereby directly transmitting a force along the axis of the roll.

A still further object of the present invention is to provide an inktransfer system utilizing such an oscillator means as characterizedwherein a pair of ring mem bers are provided for retaining the ballmember in place against the side walls of the offset groove, the ringmembers being adjustable toward and away from each other in order tovary the bearing pressure of the ball member against the groove sidewalls.

A still further object of this invention is to provide an oscillatormeans for an ink transfer system wherein the ring members as describedeach have an inner surface forming an outer race for the ball member.

A still further object of the invention is to provide a technique forrendering the fountain substantially leakproof by avoiding the need forclose clearance between each end of the fountain roll and the inner faceof each fountain cheek.

A still further object of the present invention is to provide aleakproof fountain by mounting each end of the fountain roll surfacewithin each fountain check which is relieved along its inner surface soas to direct beads of ink at each end of the fountain roll away fromeach cheek and back into the fountain reservoir.

A still further object is to provide such a relief for each cheek so asto present a sharp extension on each cheek directly aligned with theends of the fountain blade whereby any leakage between the blade endsand each relief will be directed onto the fountain roll for subsequentdeposit back into the fountain reservoir.

Other objects, advantages and novel features of the present inventionwill become apparent from the following detailed description of theinvention when considered in conjunction with the accompanying drawingswherein:

FIG. 1 is a representative showing of a typical ink train of rollsincorporating the present invention;

FIG. 2 is a side elevational view of the ink transfer roll according tothe present invention;

FIG. 3 is a fragmentary sectional view of the ink transfer roll takensubstantially along the line 3-3 of FIG. 2;

FIG. 4 is a view taken along the line 4-4 of FIG. 1 showing an assemblyof the fountain, fountain roll and fountain blade according to thepresent invention;

FIG. 5 is a side and partial sectional view taken substantially alongthe line 5-5 of FIG. 4;

FIG. 5A is a partial perspective showing the inner surface of a fountaincheek designed for preventing leakage; and

FIG. 6 is a sectional view of one end of the central roller in the inkroll train showing the oscillator means according to the presentinvention.

Turning now to the drawings wherein like reference characters refer tolike and corresponding parts throughout the several views there is shownin FIG. 1 a schematic representation of a typical ink distribution chainof rolls in a rotary printing press incorporating the improved featuresof the instant invention. A rotatable central roll 10 is thereinprovided with distribution rolls 11 being rotatably mounted insurfaceto-surface contact therewith. The rearwardmost distribution roll11' is rotatably mounted in contact with the surface of transfer roll 13of the present invention. This roll 13 is adjacent a fountain roll 14which is rotatably mounted within an ink fountain 15 in a manner to behereinafter described. At the other end of the array, the typical platecylinder 16 is rotatably mounted in contact with two of the typicallyarranged form rolls 12. The surfaces of the several rolls in the trainare alternately hard and soft so that the fountain roll 14, distributionroll 11', central roll 10 and the plate cylinder 16 may each have ametallic surface while the distribution rolls 11, the form rolls 12 andthe transfer roll 13 may each have a rubberized or polyurethane or otherresilient surface, as shown.

Transfer roll 13 is provided with a plurality of helical grooves 17 and,as can be seen in FIG. 1, consist of a total of eight grooves equallyspaced about the surface of the roll. It should be understoodyhowever,that as few as two and as many as ten grooves are permissable dependingon transfer roll diameter so that the specific number of groovesdisclosed are not required in all applications. Each of the grooves 17have only one side wall, as seen at 18 in FIG. 3, thereby presenting asharp radial surface departure as at 19 which may be referred to as atrailing edge relative to the direction of rotation of the roll as shownby the arrow. The surface of transfer roll 13 between each of thegrooves 17 is sloped between the uppermost portion of the groove sidewall 18, i.e., trailing edge 19, and the lowermost portion of the grooveside wall of an adjacent groove,.

i.e., bottom 21 of the groove. The slope is not along a straight linebut is an arc length segment having a radius R with its radial centerlying along the line L connecting the geometric center of the roll 13and the outermost periphery thereof, as clearly shown in FIG. 3 of thedrawings. The distance D from the geometric center of the roll 13 andthe radial center of line R is equal to 0.125 inches in a roll having adiameter of approximately 3.5 inches. Although FIG. 3 shows only two ofthe sloping surfaces of the roll 13, it should be understood that theabove description for tracing an are between grooves is typical betweenall grooves.

FIG. 2 clearly shows each of the grooves 17 along the surface of roll 13substantially parallel to one another and as most clearly seen forgroove 17a, each groove terminates at each end of the roll on the hiddenside of the roll surface as represented substantially by the brokenlines and 17a" for a single one of the grooves, similar showing for theremaining grooves being absent from the drawing in the interest ofclarity.

In the ink train arrangement shown in FIG. 1, the transfer roll 13 isundersped in relation to press speed so as to be rotated atapproximately 83% percent of press surface speed. The fountain roll, onthe other hand, is rotated substantially below that of press surfacespeed so that it will be rotating at a rate between 0 and 6% percent ofpress surface speed.

Returning to FIG. 3 of the drawings, it can be seen that the sloping arclength between each of the trailing edges 19 and the bottom portions 21of an adjacent groove will actually produce a leading edge, slope orramp 23.

All rolls in the system are set for a nominal squeeze contact ofapproximately 0.002 to 0.003 inch interference. This setting issufficient to provide a rolling contact between rolls of approximately/8 inch on the circumference.

The transfer roll 13 is set for normal squeeze contact against the inkdistribution roll 11' except that a running clearance is set atapproximately 0.0005 inches maximum between the transfer roll and thefountain roll 14. This running clearance is necessary to preventfrictional heating of the two rolls due to the high surface speeddifferential which can be as much as 97 percent during actual printingconditions. During operation and rotating in a direction as shown by thearrows in FIG. 1, normal transfer of ink from the fountain roll to theplate cylinder is accomplished by the wiping action of the transfer rollgenerated ramps 23 from the fountain roll to the ink distribution roll11'. While the transfer roll 13 is rotating in this same direction,reverse transfer of ink is also taking place from the transfer roll 13so that a quantity of ink is not only being removed from the fountainroll 14 but a quantity of ink is being redeposited back onto thefountain roll. Reverse transfer is, therefore, the process whereby theink film is reduced and returned to the fountain roll 14 by action ofthe helical transfer roll. Ink is deposited on the fountain roll througha spreading action and subsequent ink-split caused by the sharp side 19of the helical lead rotating against the slowly rotating fountain roll.The fountain roll is made to rotate between 0 and 6% percent of presssurface speed while the transfer roll is made to rotate approximately83%: percent of press surface speed. Reverse ink transfer through theink spreading action as aforedescribed in made possible when thetransfer roll is undersped by approximately l6% percent with respect topress surface speed. It has been found that, although reverse transferis also possible when the transfer roll is driven at press speed, therate of reverse transfer is approximately 50 percent slower as comparedto reverse transfer during the 16% percent undersped relative rate ofthe transfer roll. Because of this simultaneous forward and reversetransfer by the roll 13, ink film on the surface of distribution roll 11is actually being established by the difference between the wipingaction of the leading side or ramp 23 against the fountain roll and thedepositing action of the trailing edge 19 against the slower rotation ofthe fountain roll.

The above referred-to ink split condition is a commonly recognized termused to describe the resultant action that takes place after a given inkfilm thickness has been forced through the nip of two rolls in rollingcontact. At the point of contact, the total film thickness on one orboth rolls is blended and becomes common on both rolls as between thetransfer roll 13 and the fountain roll 14. The ink-split condition thenis the separation of the total film thickness at the point where therolls cease to make rolling contact which would be at a slight distancefrom the point of roll contact in the direction of rotation of eachroll. During ink splitting, a certain proportion of the total filmthickness remains on each roll with the proportion being approximatelyequal assuming that both rolls have identical surface speeds at thepoint of contact. The actual proportion is determined by the relativesurface speed of each roll and by the affinity of each roller surface.Therefore, the resultant ink film in the system is entirely dependent onthe volume of ink supplied by the fountain through a combination offountain film thickness and relative fountain speed. A normal printingfilm thickness of 0.0002 to 0.0004 inches is readily obtainable in theinstant system by first adjusting the film thickness through thefountain blade to approximately 0.0007 to 0.001 inches depending uponthe specific ink consistency, and thereafter regulating the rotationalspeed of the fountain roll.

The system film thickness is adjusted by varying the relative speed ofthe fountain roll over a 2:1 range of the given proportion of the presssurface speed. An electronic fountain drive (not shown) operates between3% and 6% percent of press speed, with the selected percentage beingconstant at any given press speed. The system ink film thickness maytherefore be reduced at any time by merely decreasing the proportionatefountain roll speed.

Near total reverse transfer can be effected by completely stopping thefountain roll. Indexing of the fountain roll will therefore be requiredfor this process, i.e., intermittent rotation of the fountain roll willbest serve to effect total reverse transfer or clean-up. Accordingly,the fountail roll is rotated approximately 10 to 15 in the normaldirection of rotation at which time the roll remains in a stalledposition for a maximum length of time, but not to exceed more thanseconds, this being the maximum automatic delay obtainable with anelectronic timer contemplated for use with this invention. Stalling thefountain roll in this way permits ink to be deposited on the fountainroll at the juncture of the fountain and helical transfer roll. As thedeposit increases, the fountain roll is rotated approximately l0 to 15in the direction of the arrow as shown in FIG. 1 at the maximum lengthinterval of 180 seconds as noted above. Any further rotation of thefountain roll other than as described could caused excess ink to betransferred to the system as in a normal operation. Accordingly, suchindexing of the fountain roll prevents excess accumulation and possiblerunoff during use of a more liquid ink.

For most formats the fountain roll can remain at the setting previouslydescribed during normal transfer (between 3% and 6% percent of pressspeed) since the helical transfer roll has excellent replenishmentcapabilities. However, the fountain roll blade gap setting may need tobe readjusted during such times when an unusually heavy solid may appearon the format. Under normal operating conditions, it is desirable toobtain a proper balance of fountain roll film thickness and fountainroll speed so that the fountain roll speed is in the lower range of theelectronic drive. This will tend to reduce any hydraulic action that mayoccur in the fountain, i.e., the dynamic force that tends to vary thefountain blade gap setting and thus vary the film thickness delivered bythe fountain roll. This dynamic force is known to be caused by therotation of the fountain roll past the stationary fountain blade. Theactual force is developed through the ink itself as it is forced betweenthe blade and fountain roll. Though the blade must be flexible to allowfor minute gap adjustments across the roll, it is also susceptible tothe hydraulic force applied at the juncture of the blade and fountainroll. Also, the hydraulic action varies with the speed of the fountainroll as well as with the viscosity of the ink. Forcing the ink throughthe blade gap also generates heat which is dependent upon the fountainroll speed and gap setting of the blade. Excessive heat will vary theviscosity of the ink and will cause a change in the fountain roll inkfilm thickness. It is, therefore, desirable to keep the speed of thefountain roll as slow as possible.

To summarize, it can be seen that the transfer action of the helicaltransfer roll 13 is effected by the rolling contact of the generatedramp 23 of each lead on the surface of the transfer roll. Each lead hasan almost complete wiping action against the fountain roll due to thehigh surface speed differential of the transfer roll and fountain roll.Replenishment or transfer capability of the transfer roll thereforebecomes less efficient as this rate of speed differential increases. Onthe other hand, return transfer or reverse transfer becomes moreeffective as this speed differential increases.

The amount of ink wiped from the fountain by each lead on the surface ofthe transfer roll is immediately transferred to the ink distributionroll 11' and thereafter to the distribution rolls ll, 10 and finally tothe plate cylinder 16 through the form rolls 12. The sharp side ortrailing edge 19 makes contact at approximately a 16% percent slowersurface speed with the ink distribution roll 11' where a small amount ofink is thereupon forced into the radius of the groove 17 and is splitand returned to where it again makes contact with the fountain roll.Because of the relative speeds of the rolls ll, 13 and 14 and due totheir relative positions to each other as seen in FIG. 1, contact ismade at the same radial position on the fountain roll where the film hasbeen wiped by the leading edge of the same lead. At this point, thefountain film thickness is much less than the deposit on the trailingedge of the transfer roll lead. This reduced film thickness of thefountain roll and the deposit of the transfer roll combine andsubsequently split through a spreading action caused by differentialrolling contact thereby leaving a portion of the deposit on the fountainroll. When no ink is being consumed by the system and when an ink filmbalance has been achieved, i.e. the point at which equal amounts of inkare transferred in both directions, the helical transfer roll merelyacts as a recirculating device. Therefore, when both ends of the rollcluster have identical film thickness, the ink film is merelyrecirculated through the ink-splitting process occurring at each rollcontact.

Cleaning of the system can be readily accomplished more easily andefficiently by utilizing the reverse transfer function of the helicaltransfer roll. One way for accomplishing this reverse transfer would beto replace the fountain 15 with one containing no ink and adjust itsfountain blade 24 so as to wipe the fountain roll clean. With the systemoperating in the normal direction of roll rotation as shown by thearrows in FIG. 1, no ink would he therefore supplied to the transferroll 13. However, ink would be deposited on the clean fountain roll bythe trailing side or edge 19 of each lead. This ink would be returned tothe fountain reservoir area at which point it would be wiped from thefountain roll by the blade 24. An average system film thickness shouldbe returned within a time equivalent of 1,000 to 1,5000 surface feet ofrotation, at which point a negligible film thickness may remain.Addition of cleaning solvent on the system rolls at this point wouldthen remove most of the balance of the film.

An alternative technique for use during reverse ink transfer would be tocompletely stall the fountain roll or stall it to a negligible R.P.M.while the press is in the ink-up mode. This technique operates on muchthe same principle as the use of the clean fountain roll since no oronly a negligible amount of ink is supplied to the transfer roll. Ink isdeposited by the trailing edge of each lead at a point after the nip ofthe two rolls 13 and 14 causing an accumulation of ink to form at thispoint. Since this accumulation is formed after the nip, the normalwiping action of the leading ramp of each lead is not effective, and thelead tends to force the accumulated ink away from the nip rather thaneffect a transfer. As the accumulation increases on the fountain roll toa point of possible run-off or gravity transfer, the fountain roll mustthen be rotated toward the reservoir, if completely stalled.

Referring again to FIG. 1 of the drawings, it can be seen that thefountain blade 24 is mounted within the fountain 15 substantially belowthe level 1 of ink contained within the fountain. In FIGS. 4 and 5, itcan be seen that the fountain 15 comprises an elongated bottom or platemember 25 for supporting a quantity of ink and having end or cheekmembers 26 and 27 each suitably secured thereto as by fasteners 28.Cheek members 26 and 27 serve as end walls for containing the ink and asa means for mounting the fountain roll 14, shown in FIG. 5 as beingjournaled for rotation with a suitably provided aperture 30 in endmember 26. The fountain blade 24 extends between the respective interiorsurfaces 26a, 27a of each of the end members and is provided with anumber of cutout portions 29 which, during assembly, permit the fountainblade to be adjusted relatively to the fountain roller against a pair ofstop pins 31 clearly shown in both FIGS. 4 and 5. An elongated bladeclamp 32, having a number of threaded apertures 33 therealong forthreaded engagement with a like number of threaded studs 40, serves asan elongated hold-down means for securing one end of the fountain blade24 in place after wing nuts 34 are sufficiently tightened about studs40. A plurality of apertures 35 are also provided along the length ofbase member 25 and are internally threaded for the reception ofaplurality of thumb screws 36 whereby an accurate adjustment of theforward edge of the fountain blade can be made along its entire length.Accordingly, the blade 24 may be first inserted into the fountain 15 soas to lie in contacting engagement with surfaces 26a, 2711 at each sideand against stop pins 31 at its forward end. Wing nuts 34 are thentightened and, by means of thumb screws 36, the blade gap is adjustedfor regulating the amount of ink desired to be extruded through theblade.

Each of the inner surfaces 26a, 27a of the cheek members 26 and 27 isslightly relieved as at 37 in the vicinity of aperture 30, as seen inFIG. A, so that the width of each cheek at the relieved area isapproximately 1/16 inch less than the width of the remainder of eachcheek. As shown, the unrelieved portion of the cheek terminates at anend cap 37' defined by a downwardly extending wall substantiallyperpendicular to blade 24 and to face 270 so that any leakage betweenface 27a and the side edge of the blade will occur at a distance equalto the relief forwardly of end cap 37'. The diameters of the aperture 30and fountain roll are substantially equal so that the fountain roll endsare each received wholly within the aperture 30 of each cheek.Accordingly, any leakage between the cheek inner faces and the bladeends will result in beads of ink being directed onto a portion of thefountain roll surface, rather than hugging the inner face of each cheekwhere accumulation of ink normally builds up and subsequently dripsdownwardly. The undesirable beads of ink directed onto the fountain rollsurface, therefore, are directed back into the fountain reservoir as thefountain roll continues to rotate. In order to ensure that these beadswill not cause an undue amount of ink accumulation at the faces 26a,270, a chamfered wall section 37" is provided for the upper section ofthe relief, as shown clearly in FIG. 5A. Pressure buildup, occasioned byhydraulic action of the ink at either end of the fountain roll, isthereby relieved somewhat so that any leakage through the fountain maybe held to a minimum.

It has been found that with an adjustment of the fountain blade againstthe fountain roll to effect a fountain film thickness between 0.0007 and0.0010 inches, and with the fountain drive in the low speed range, theresultant film thickness should be about 0.0002 to 0.0003 inches, whichis in the lower portion of the normal printing range. If the film is notsufficient for the format and ink being used, the thickness may beincreased by merely increasing the relative speed of the fountain roll.Conversely, if the ink film becomes excessive, the system film thicknessmay be reduced by either reducing the relative speed of the fountain orby reducing the fountain roll film thickness by narrowing the blade gap.

A simple unique oscillating mechanism for the sun axle 38 of the centraldistribution roll has also been devised for the instant rotary printingpress (see FIG. 6). The mechanism consists of an offset sun groove' orball race 39 similar to a barrel cam having a true pitch circle whichcontacts a single planetary ball 42 and which forms the pitch circle ofthe planetary ball, thus creating a ratio between pitch circles of thesun groove and planetary ball. The planetary ball 42 also makes contactwith an outer annular groove or ball race 40 which also has a pitchdiameter created by the angle of contact of the planetary ball. Thisangular contact may, as in the instant invention, create another pitchcircle about the planetary ball. Thus, the planetary ball has one pitchcircle relative to the sun groove 39 and a different pitch circlerelative to the outer groove 40. The oscillation ratio of the sun grooveis dependent upon a total of these ratios determining the planetaryspeed of the ball relative to the sun axle. It can be seen, therefore,that infinite oscillation ratios can be established by differentiallyrotating both the sun axle 38 and the outer annular race 40 or bycompounding an offset outer race with the offset sun axle race. In theinstant invention, one complete oscillation occurs upon one revolutionof the planetary ball 42 around the sun axle 38, producing anoscillation rate of approximately 2 sun axle revolutions to one completeoscillation depending on the size of the sun groove 39 and the planetaryball 42.

The offset sun groove 39 is formed by a pair of side walls 41 converginginwardly for the two-point reception of the planetary ball member 42mounted between a pair of ring members 43 within a mounting cap 44 and asleeve member 45. The inner wall of each ring member is tapered as shownso as to present a pair of outwardly diverging walls within which theball member 42 may be rotated while in contact with the side walls 41 ofthe groove 39. In this way, as the axle 38 is rotated, axial movementthereof will be effected between a leftward extent at the ball positionseen in FIG. 6 and a rightward extent as when the axle is rotatedthrough bringing the rearmost location of the groove 39 in contact withthe ball 42. Any necessary adjustment of the bearing force of the ballagainst the side walls 41 can be accomplished by simply moving the ringmembers toward and away from each other thereby respectively increasingand decreasing the bearing force against side walls 41. Adjustmentscrews 46 (only one of which is shown) and shims 50 are provided forthis purpose.

From the foregoing, it can be seen that an ink transfer system has beendevised for improving the efficiency and transfer capabilities, for thevarious ink consistencies, of a transfer roll in use with rotaryprinting presses. The instant helical transfer roll, which can be easilyinstalled and replaced in most printing press systems, assures a moreperfect balance of ink film in the system as compared to other knowndevices. The unique design of the transfer roll surface allows an inkvolume to be transferred consistent or equal to the usage requirementsat any given point or area on the roll surface as determined by theprinted image. The rate of transfer is varied by adjusting the speed ofthe fountain roll against the transfer roll running at less than presssurface speed. Because both forward'and reverse transfer is effectedwith this design, not only is complete reverse transfer possible asduring a clean-up operation, but the system is capable of being runindependently of the press thereby allowing the appropriate ink film tobe established on all rolls without the actual running of the press.Contrary to some conventional continuous web presses, this would createa considerable waste product. However, without ink being consumed by thesystem, the ink transfer system, according to the present invention,will serve to merely recirculate the ink film between the fountain anddistribution rolls during an ink film balance condition. Also, a simplebut highly efficient manner of preventing leakage from the fountain hasbeen devised simply through the use of a fountain blade which is closelyaligned with an end cap relief on the inner face of each cheek so thatany leakage will result in beads of ink being directed onto the fountainroll and back into the fountain reservoir. Furthermore a smoothoscillation of the rolls is effected by means of the instant oscillationtechnique in a manner which is simpler, more economical and requiresless maintenance as compared to other known techniques because theinstant device is an integral part of the oscillating axle and thereforeexerts almost a totally direct axial force to effect oscillation.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. For example, the ink trainof rollers may be slightly rearranged so that the transfer roll is indirect contact with the central distribution roll whereby an even moreink balanced system is effected because of the capability of thetransfer roll to replenish ink in an almost direct ratio to ink removal.It is therefore to be understood that within the scope of the appendedclaims the invention may be practiced otherwise than as specificallyclaimed.

What is claimed is:

1. an ink fountain designed for substantially preventing the leakage ofink therethrough comprising: a fountain reservoir having end members; abottom support plate; and an adjustable fountain blade extending betweenthe inner face of each said end member near the lower portion thereof;each said end member having an aperture therein substantially equal indiameter to the diameter of a fountain roll to be snugly received withineach said end member aperture, the width of each said end memberforwardly of said fountain blade being slightly smaller in the vicinityof said apertures than the width of the remainder of each said endmember, said slightly smaller end member width defining a reliefsection, one end of said relief section being defined by a downwardlyextending wall surface coplanar with the inner edge of said fountainblade, said wall section lying perpendicular to each said inner face,whereby heads of ink may be directed on to said fountain roll in theevent of leakage at said end member faces so that the beads of ink maybe directed back into said reservoir.

2. The fountain according to claim 1 wherein the other end of saidrelief section is defined by a chamfered wall section for substantiallypreventing any undue accumulation of ink caused by said beads againsteach said inner face after being directed back into said reservoir.

1. AN INK FOUNTAIN DESIGNED FOR SUBSTANTIALLY PREVENTING THE LEAKAGE OFINK THERETHROUGH COMPRISING: A FOUNTAIN RESERVOIR HAVING END MEMBERS; ABOTTOM SUPPORT PLATE; AND AN ADJUSTABLE FOUNTAIN BLADE EXTENDING BETWEENTHE INNER FACE OF EACH SAID END MEMBER NEAR THE LOWER PORTION THEREOF;EACH SAID END MEMBER HAVING AN APERTURE THEREIN SUBSTANTIALLY EQUAL INDIAMETER TO THE DIAMETER OF A FOUNTAIN ROLL TO BE SNUGLY RECEIVED WITHINEACH SAID END MEMBER APERTURE, THE WIDTH OF EACH SAID END MEMBERFORWARDLY OF SAID FOUNTAIN BLADE BEING SLIGHTLY SMALLER IN THE VICINITYOF SAID APERTURES THAN THE WIDTH OF THE REMAINDER OF EACH SAID ENDMEMBER, SAID SLIGHTLY SMALLER END MEMBER WIDTH DEFINING A RELIEFSECTION, ONE END OF SAID RELIEF SECTION BEING DEFINED BY A DOWNWARDLYEXTENDING WALL SURFACE COPLANAR WITH THE INNER EDGE OF SAID FOUNTAINBLADE, SAID WALL SECTION LYING PERPENDICULAR TO EACH SAID INNER FACE,WHEREBY BEADS OF INK MAY BE DIRECTED ON TO SAID FOUNTAIN ROLL IN THEEVENT OF LEAKAGE AT SAID END MEMBER FACES SO THAT THE BEADS OF INK MAYBE DIRECTED BACK INTO SAID RESERVOIR.
 2. The fountain according to claim1 wherein the other end of said relief section is defined by a chamferedwall section for substantially preventing any undue accumulation of inkcaused by said beads against each said inner face after being directedback into said reservoir.